ON THE MEASUREMENT OF SHIPS FOR TONNAGE, 69 
It is found in practice that the actual working-power of marine engines, 
with reference to their nominal horse-power, fluctuates upwards of 100 per 
cent., and on the general average of the practice of the present day, it 
appears that the unit of marine engine horse-power is equivalent to 100,000 
Ibs. raised one foot high per minute of time, being equal to three times the 
unit denominated “ Indicated Horse-power” (viz. 33,000 lbs. raised one foot 
high per minute). 
It appears to your Committee that the legalization by statute of some 
standard unit of power is an indispensable requirement of the age; and the 
question is, whether 33,000 lbs. or 100,000 Ibs. raised one foot high per 
minute, shall be recognized and legalized as the standard unit of power to 
which the registration of marine engine-power should have reference. 
That the unit designated by 100,000 lbs. raised one foot high per minute, 
would nearly approach the working capability per nominal horse-power of the 
present marine engines, is admitted; but conceiving that a registration of 
engine capability would still not give all the information as to the engines 
which registration ought to embrace, your Committee recommend that the 
registration of marine engines should, in addition to their capability, embrace 
the number and diameter of the cylinders, and length of stroke, or other indi- 
cation of the size of engine, according to its construction, as well as the number 
and size of the boilers, and total area of the fire-grates, whereby the size 
and quantity of the machinery on board, irrespective of its capability for 
working power, may be at any time compared with the registered description 
thereof. 
The Committee supposed it important to confine the Report to those points 
-on which a definite and almost unanimous opinion could be given. With 
respect to the question relating to the registration of weight-tonnage and 
displacement, after maturely considering the evidence, the Committee did not 
agree in such a manner as to be able to recommend this portion of the subject 
for legislative enactment. 
(By order of the Committee) HARpDWICKE, 
May 27, 1857. Chairman. 
APPENDIX. 
No. I.—Circutar.—7o the respective Members of the Committee appointed 
by the British Association “ to inquire into the defects of the present methods, 
and to frame more perfect rules for the Measurement and Registration of 
Ships and of Marine Engine Power, in order that a correct and uniform 
principle of estimating the actual Carrying Capabilities and Working Power 
of Steam Ships may be adopted in their future Registration.” 
Sir,—Rear- Admiral the Right Honourable the Earl of Hardwicke having 
been nominated by the members of the Tonnage Committee, “to officiate as 
permanent chairman for conducting (with the assistance of a private secre- 
tary, whom his Lordship may be pleased to nominate) the proceedings of this 
_ Committee,” his Lordship has directed me as Secretary (pro tem.) to request 
that the members of this Committee will be pleased to meet at the Hall of the 
Society of Arts, Adelphi, London, on Thursday, Ist January next, at eight 
_ o'clock p.M., to take into consideration the business assigned to this Com- 
_Inittee, especially with a view to concerting as to the points of statistical 
inquiry on which this Committee may require to avail themselves of the co- 
